A look at the most important thing each team needs to do or change as we enter a new calendar year and Formula One season, concluding with the teams who finished in the top half of the standings in 2017.

Williams

Make its driver line-up decision for the right reasons

Sergey Sirotkin has emerged as favourite for the vacant Williams seat. Sutton Images

Williams goes into the new season owning the only missing piece of the 2018 grid. The search for Lance Stroll's teammate will continue into the new year, with Robert Kubica and Russian youngster Sergey Sirotkin the two favourites for the seat. Sirotkin, backed by an estimated £15 million from Russia's SMP Racing, reportedly emerged as the number one prospect in the days after the Abu Dhabi test, where both men featured. Daniil Kvyat is believed to still have an outside shot as the back-up option.

Reports suggested Sirotkin's elevation was linked to his performance in Abu Dhabi, though any driver bringing in that amount of money is always going to be viewed as a product of a finances until they can prove otherwise (something Sirotkin obviously deserves the chance to do if he gets the nod). Hopefully the performance consideration will outweigh any other factors -- it would be a shame if a team with a history as rich as Williams' simply made another line-up decision based on who was the highest bidder.

Force India

Ensure warring drivers don't cost valuable points

Teammates Sergio Perez and Esteban Ocon struggled to race each other cleanly in 2018. Photo by Getty Images/Getty Images

Force India has been superb in recent seasons -- back-to-back fourth-place finishes, for a team on a limited budget, has been an incredible achievement. The most recent campaign was perhaps its most impressive, as it stayed consistently the fourth best team from start to finish. The only blot on 2017 was how the team mismanaged Sergio Perez and Esteban Ocon at times -- Perez's refusal to move over arguably cost Ocon a shot at a podium in Canada, before they squandered a chance at Baku by colliding. A further collision occurred in Belgium, despite the team publicly rebuking its drivers.

Last year, with Force India's midfield rivals caught in their own fight lower down the order, those incidents did not cost the team anything substantial in terms of the championship. With McLaren now equipped with a competitive power unit, Renault on the rise and Williams looking to force its way up the pecking order, Force India cannot afford to leave points on the table if it wants to consolidate fourth position (or better) in 2018.

Red Bull

Win with Renault power or find a solution for 2019

Red Bull must make itself the team to beat in 2018. Dan Istitene/Getty Images

A significant part of Red Bull's failure to produce a championship-winning package in the V6 turbo era has been linked to engine supplier Renault being unable to match the performance of Mercedes and, in 2017, Ferrari. The team grew in competitiveness as last season progressed and seems to be in a good place going into the new campaign, bolstered by what is arguably the strongest driver line-up on the grid. But as last year showed, Renault cannot shoulder all the blame -- a strong start to the season is imperative if it wants to win the title.

In the short-term, Red Bull will obviously want a championship in 2018, but its long-term focus will be on just securing a winning solution for the future. It will be monitoring the progress of Honda at junior team Toro Rosso and that looks like a viable option when its Renault deal ends. If Honda's struggles continue, Red Bull will have a real job on its hands to find an engine supply that can win it a championship before the regulations change again for 2021. Regardless of on-track results, what happens behind the scenes over the next 12 months will play a big part in shaping the next few years of Red Bull's F1 tenure.

Ferrari

Ferrari made waves at the end of 2017 by threatening to walk away from F1 unless the current engine proposal for the next set of regulations is changed. The team has previous in doing this -- it issued a similar declaration in 2009 about an FIA plan to implement a budget cap. That means they've been more successful in threatening to leave the sport in the last decade than at winning titles -- the team's last was the 2008 constructors' championship.

Last year showed Maranello is more than capable of putting together a package with championship potential. While Ferrari has always seemed like a team consumed with the politics of the sport it proclaims to be bigger than, its lack of championship success in recent seasons is hard to ignore. Formula One is changing and its new owners seem to be unmoved by Ferrari's latest stint of posturing. Instead of threatening to walk away or set up a rival series (both of which seem highly unlikely) a better way for Ferrari to prove how valuable it remains to the series would be to stop the talking and actually win it.

Mercedes

Secure a deal to keep Lewis Hamilton in F1 long-term

Mark Thompson/Getty Images

The signing of Lewis Hamilton has been manna from heaven for Mercedes' F1 team and its company board in Stuggart. Its aligned its brand with motor racing's biggest icon at a time when both team and driver have found a new level of performance. Hamilton's talent helped the team beat what looked to be a superior Ferrari package in 2017 and it is hard to imagine the team wilfully continuing without him.

He enters a contract year in 2018 and that will likely be the proverbial elephant in the room until there is a resolution. Discussions about a new deal are "on a good way", according to team boss Toto Wolff, but with Hamilton's interests away from F1 growing all the time an extension is by no means a certainty until there's ink on the contract. The four-time world champion has hinted at a desire to stay for at least one more contract cycle and its clear he has never felt happier in himself and about his career prospects than he does right now -- the onus is now on Mercedes to keep its star signed on until at least the next regulation change in 2021.